1 /*
2 * Copyright 2013 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8 #include "include/core/SkStream.h"
9 #include "src/pdf/SkPDFResourceDict.h"
10 #include "src/pdf/SkPDFTypes.h"
11
12 // Verify that the values of enum ResourceType correspond to the expected values
13 // as defined in the arrays below.
14 // If these are failing, you may need to update the kResourceTypePrefixes
15 // and kResourceTypeNames arrays below.
16 static_assert(0 == (int)SkPDFResourceType::kExtGState, "resource_type_mismatch");
17 static_assert(1 == (int)SkPDFResourceType::kPattern, "resource_type_mismatch");
18 static_assert(2 == (int)SkPDFResourceType::kXObject, "resource_type_mismatch");
19 static_assert(3 == (int)SkPDFResourceType::kFont, "resource_type_mismatch");
20
21 // One extra character for the Prefix.
22 constexpr size_t kMaxResourceNameLength = 1 + kSkStrAppendS32_MaxSize;
23
24 // returns pointer just past end of what's written into `dst`.
get_resource_name(char dst[kMaxResourceNameLength],SkPDFResourceType type,int key)25 static char* get_resource_name(char dst[kMaxResourceNameLength], SkPDFResourceType type, int key) {
26 static const char kResourceTypePrefixes[] = {
27 'G', // kExtGState
28 'P', // kPattern
29 'X', // kXObject
30 'F' // kFont
31 };
32 SkASSERT((unsigned)type < SK_ARRAY_COUNT(kResourceTypePrefixes));
33 dst[0] = kResourceTypePrefixes[(unsigned)type];
34 return SkStrAppendS32(dst + 1, key);
35 }
36
SkPDFWriteResourceName(SkWStream * dst,SkPDFResourceType type,int key)37 void SkPDFWriteResourceName(SkWStream* dst, SkPDFResourceType type, int key) {
38 // One extra character for the leading '/'.
39 char buffer[1 + kMaxResourceNameLength];
40 buffer[0] = '/';
41 char* end = get_resource_name(buffer + 1, type, key);
42 dst->write(buffer, (size_t)(end - buffer));
43 }
44
resource_name(SkPDFResourceType type)45 static const char* resource_name(SkPDFResourceType type) {
46 static const char* kResourceTypeNames[] = {
47 "ExtGState",
48 "Pattern",
49 "XObject",
50 "Font"
51 };
52 SkASSERT((unsigned)type < SK_ARRAY_COUNT(kResourceTypeNames));
53 return kResourceTypeNames[(unsigned)type];
54 }
55
resource(SkPDFResourceType type,int index)56 static SkString resource(SkPDFResourceType type, int index) {
57 char buffer[kMaxResourceNameLength];
58 char* end = get_resource_name(buffer, type, index);
59 return SkString(buffer, (size_t)(end - buffer));
60 }
61
add_subdict(const std::vector<SkPDFIndirectReference> & resourceList,SkPDFResourceType type,SkPDFDict * dst)62 static void add_subdict(const std::vector<SkPDFIndirectReference>& resourceList,
63 SkPDFResourceType type,
64 SkPDFDict* dst) {
65 if (!resourceList.empty()) {
66 auto resources = SkPDFMakeDict();
67 for (SkPDFIndirectReference ref : resourceList) {
68 resources->insertRef(resource(type, ref.fValue), ref);
69 }
70 dst->insertObject(resource_name(type), std::move(resources));
71 }
72 }
73
make_proc_set()74 static std::unique_ptr<SkPDFArray> make_proc_set() {
75 auto procSets = SkPDFMakeArray();
76 static const char kProcs[][7] = { "PDF", "Text", "ImageB", "ImageC", "ImageI"};
77 procSets->reserve(SK_ARRAY_COUNT(kProcs));
78 for (const char* proc : kProcs) {
79 procSets->appendName(proc);
80 }
81 return procSets;
82 }
83
SkPDFMakeResourceDict(const std::vector<SkPDFIndirectReference> & graphicStateResources,const std::vector<SkPDFIndirectReference> & shaderResources,const std::vector<SkPDFIndirectReference> & xObjectResources,const std::vector<SkPDFIndirectReference> & fontResources)84 std::unique_ptr<SkPDFDict> SkPDFMakeResourceDict(
85 const std::vector<SkPDFIndirectReference>& graphicStateResources,
86 const std::vector<SkPDFIndirectReference>& shaderResources,
87 const std::vector<SkPDFIndirectReference>& xObjectResources,
88 const std::vector<SkPDFIndirectReference>& fontResources) {
89 auto dict = SkPDFMakeDict();
90 dict->insertObject("ProcSet", make_proc_set());
91 add_subdict(graphicStateResources, SkPDFResourceType::kExtGState, dict.get());
92 add_subdict(shaderResources, SkPDFResourceType::kPattern, dict.get());
93 add_subdict(xObjectResources, SkPDFResourceType::kXObject, dict.get());
94 add_subdict(fontResources, SkPDFResourceType::kFont, dict.get());
95 return dict;
96 }
97